The need for a given resource is often characterized by a temporal characteristic and a scalar characteristic, in the sense that a need for a limited, finite portion of a particular resource may arise at a particular time and last for a finite duration of time, after which the resource can be returned and reissued to another user or reapportioned and shared amongst a collection of other users, whose individual needs (which are limited in scale and time on an individual basis) can be aggregated to a scale that permits and implicates the creation and efficient distribution of a sharable, divisible resource. The recognition of the temporal and scalar aspect of resource allocation has given rise to the use of resource allocation structures that allow for portions of a shared resource to be temporarily assigned to user, who becomes responsible for returning the portion of the shared resource after a prescribed period of time.